best way to use AES Encryption in QT

[saeid0034]

hi sorry if this question is bad or i post it on wrong forum

i need to use AES-256/CBC Encryption for one of my project
first i try to use Botan lib for doing this job (i follow This tutorial) but sadly after fully write the code i get this error

cannot find -lbotand
collect2.exe: error: id returned 1 exit status

i dont know i get this error for what (also i cant find any good information about this error in internet)
i also use Qt-AES but its give me lots of error too

anyone can help me to find a good way for use AES-256/CBC Encryption for Encrypt String in QT?

[SGaist]

Hi,

Did you install the botan development package ?

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

Hi,

Did you install the botan development package ?

thanks for reply
i only build botan from source code (with nmake)
can you tell me where i can get botan development package

[SGaist]

Nothing wrong with using your own self built version.
Where did you install the library ?
Do you have the library file ending with a d ?

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

Nothing wrong with using your own self built version.
Where did you install the library ?
Do you have the library file ending with a d ?

i only have botan.lib in C:\Botan\lib
and i cant find library file ending with a d
I also build botan based of guide in https://botan.randombit.net/handbook/building.html

[SGaist]

Then you should link to botan and not botand.

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

Then you should link to botan and not botand.

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/../../../../../Botan/lib/ -lbotan
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/../../../../../Botan/lib/ -lbotand

INCLUDEPATH += $$PWD/../../../../../Botan/include
DEPENDPATH += $$PWD/../../../../../Botan/include

when i add lib on qt this line add in pro file
also when i delete else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/../../../../../Botan/lib/ -lbotand i got more error
everything seems good until i try to compile

[SGaist]

Either you need to also build botan in debug mode so you have the two versions of the library or you change the .pro file to always link to the version you have built.

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

Either you need to also build botan in debug mode so you have the two versions of the library or you change the .pro file to always link to the version you have built.

when i edit pro file and remove other one its give me more error
how can i build debug version of botan?

[SGaist]

Because you removed the line trying to link to botand -and you likely have now a lot of undefined symbols.

Just use:

LIBS += -L$$PWD/../../../../../Botan/lib/ -lbotan

As for building botan in debug mode, tell cmake you want a Debug build.

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

LIBS += -L$$PWD/../../../../../Botan/lib/ -lbotan

I test what you say
this time i get even more error

my .pro

LIBS += -L$$PWD/../../../../../Botan/lib/ -lbotan

INCLUDEPATH += $$PWD/../../../../../Botan/include
DEPENDPATH += $$PWD/../../../../../Botan/include

my full code:

#include "mainwindow2.h"
#include "ui_mainwindow2.h"
#include "botan/botan.h"
#include "botan/pipe.h"
#include "botan/aes.h"
#include "botan/filters.h"

MainWindow2::MainWindow2(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow2)
{
    ui->setupUi(this);
    Botan::InitializationVector init;
}

MainWindow2::~MainWindow2()
{
    delete ui;
}

void MainWindow2::on_pushButton_clicked()
{
    Botan::AutoSeeded_RNG rng;
    Botan::SymmetricKey key(rng,32);
    Botan::InitializationVector IV(rng,16);
    Botan::Pipe pipe(Botan::get_cipher("AES-256/CBC",key,IV,Botan::ENCRYPTION),new Botan::Hex_Encoder);
    pipe.process_msg(ui->textEdit_input->toPlainText().toStdString());
    std::string m1=pipe.read_all_as_string(0);
    ui->textEdit_output_E->setText(QString::fromStdString(m1));
}

[SGaist]

Are you sure that the library was built for thé same architecture as the Qt version you are using ?

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

Are you sure that the library was built for thé same architecture as the Qt version you are using ?

i see a video in yotube use botan 1.10.8 on QT 4.8.5
you think its not support new verson of qt?

[SGaist]

You should use the latest version of botan for security reasons.

In any case, it's completely unrelated to my question: aare the architectures of your botan build and Qt the same ?

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

You should use the latest version of botan for security reasons.

In any case, it's completely unrelated to my question: aare the architectures of your botan build and Qt the same ?

sorry for this question, but how i cant found out (im new at c++ and qt)

[SGaist]

You can use dumpbin as explained here

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

You can use dumpbin as explained here

i check botan-ci.exe, here is result

and here is botan.dll

both is 64bit
and also my qt compiler is 64bit too

[SGaist]

Did you also compile botan with MinGW ?

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

Did you also compile botan with MinGW ?

no i compile it with nmake
i need to compile it with MiniGW?

[SGaist]

If you used nmake, it means that in fact you used Visual Studio to build botan. So there's your issue. You can't mix C++ code built with MinGW with C++ code built with Visual Studio.

Tow options here:

• rebuild botan using MinGW
• change your Qt version and use the one that matches your Visual Studio version

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

If you used nmake, it means that in fact you used Visual Studio to build botan. So there's your issue. You can't mix C++ code built with MinGW with C++ code built with Visual Studio.

Tow options here:

• rebuild botan using MinGW
• change your Qt version and use the one that matches your Visual Studio version

you recommend what version of qt for this?
i think its beter to compile botan again..

[SGaist]

As I said: the one matching your current version of Visual Studio.

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

As I said: the one matching your current version of Visual Studio.

sorry i made a mistake
I mean, which version of mingw do you recommend?

[SGaist]

Use the one from your Qt installation.

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

Use the one from your Qt installation.

ok i start make with mingw32-make.exe located in Qt\Tools\mingw810_64\bin

[saeid0034]

@SGaist said in best way to use AES Encryption in QT:

Use the one from your Qt installation.

thanks for all your help
by build botan with miniGW